When Kacy & Clayton premiered “The Light of Day” from their new LP The Siren’s Song back in June, it was a marked change from what the Canadian duo had previously released. That wasn’t such a surprise: With Wilco’s Jeff Tweedy in the producer’s chair, the cousins’ bedroom folk was given the full-band treatment, transformed into something bordering on rock music. Their latest song, “A Lifeboat,” splits the difference in sound but loses none of the group’s eerie knack for storytelling.

The lifeboat that Kacy Anderson sings of in the new song is a vessel of escape more than it is a means of reaching safety. Drinking, sex, envy – none of them quell the discontent at the heart of the song, a lyrical tempest that’s contrasted with the brushed drumming and sun-kissed steel guitar that accompany her cousin Clayton Linthicum’s acoustic guitar. “Why’d you give yourself away when you know that you are mine?” asks the narrator, who could be a spouse or lover, or maybe just a jealous onlooker; it’s never quite made clear.

“A Lifeboat” is a spare, more subdued companion piece to the rollicking predecessor “The Light of Day,” but it complements that song’s domestic anxiety and its sinister music video. Working with Tweedy has likely helped expand the band’s musical palette. “[Tweedy] knows so much about recording, music and gear that it’s overwhelming, but we have a lot in common with him in regards to our tastes of production and albums from the Sixties and Seventies,” Anderson told Rolling Stone Country earlier this year.

Kacy & Clayton will release The Siren’s Song, their third full length, August 18th on New West Records. They’ll be celebrating its release with a string of shows back home in Canada this month and next, with their next performance August 9th at Wood Mountain Rodeo Ranch Museum in Wood Mountain, Saskatchewan.